Really loud feedback, NOT ground loop!

[KaMiKaZi_t0M 10+ year member]

Alrightm well I'm thouroughly confused. Today I tried to switch my subs over to my 800w amp (crunch audio) becuase the stock sub amp (visonik, yeah i kno it sucks but I'm poor) one of the channel's blew. So I pulled out my HU, and swapped the RCA's. After that, I powered the HU on and heard loud thumping noises comeing from everything powered by an amp. I quickly changed the rca's back to the other setting, still loud, pulsating feedback. I only get the sound through the amp'ed speakers, not through my dash speakers that get power on my HU.

Thing's I've tried:

Direct ground to the battery. No help, exact same noises.

I don't understand, I have power direct from the battery, and a ground directly to the battery. Could this be a problem with my Headunit? It's a Pioneer DEH-P6800MP.

Please, help, I'm sick of listening to my dash speakers, I want my thump back =[

Many thanks,

Tom

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[jerryrobinson 10+ year member]

dont change the rcas on the radio,unhook and switch the speaker outputs comming from the amps,then swap the rca inputs going into the amps,on the amps,dont go behind the radio for nothing

 

[Atimm693 10+ year member]

Plug an MP3/CD player into your amp with an adaptor and then see if the feedback is still there, if it is its the amp, if its not its the HU/RCAs.

 

[KaMiKaZi_t0M 10+ year member]

Thanks for the quick replies guys. The reason I wanted to change the rca's back there is that I have a special "sub woofer" output that links with my HU. And the sound is still there when a CD is playing, but you can kind of hear music in it too. I don't know how the RCA's would drastically stop working correctly at the same time. If I had a wire on the HU grounding out or not attached properly would that cause this happen. Do you think the HU is broken or something? Any other tests I can run to rule some other stuff out?

Thanks,

Tom

 

[mdillon 10+ year member]

my friend has that HU too. had the same exact problem. send the HU back.

 

[KaMiKaZi_t0M 10+ year member]

**** eBay!

You really think there's no way for me to fix this other than a new head unit?

Christ being poor sucks.

Tom

 

[mdillon 10+ year member]

yeah we troubleshot the same problem. ended up switching the hu from pioneer to alpine and problem went away. so we both are assuming it was the hu.

 

[rhdintegxsi 10+ year member]

it happends with pioneer decks all the time, im a bestbuy installer and i have had rca preout feedback too many times. Not once have i had the same issue with alpine though.

 

[KaMiKaZi_t0M 10+ year member]

Oh well, this really sucks. I liked the headunit too. Any opinions on a New Alipine HU to get?

Thanks guys,

Tom

 

[mdillon 10+ year member]

maybe you can try grounding the rca's, it might help.